From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chris Wilson , Daniel Vetter , Jani Nikula Subject: [PATCH 3.13 06/46] drm/i915: Disable stolen memory when DMAR is active Date: Fri, 28 Mar 2014 10:31:50 -0700 Message-Id: <20140328173135.501262276@linuxfoundation.org> In-Reply-To: <20140328173134.630198216@linuxfoundation.org> References: <20140328173134.630198216@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chris Wilson commit 0f4706d2740f2a221cd502922b22e522009041d9 upstream. We have reports of heavy screen corruption if we try to use the stolen memory reserved by the BIOS whilst the DMA-Remapper is active. This quirk may be only specific to a few machines or BIOSes, but first lets apply the big hammer and always disable use of stolen memory when DMAR is active. v2 by Jani: Rebase on -fixes, only look at intel_iommu_gfx_mapped. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=68535 Signed-off-by: Chris Wilson Reviewed-by: Daniel Vetter Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/i915_gem_stolen.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -201,6 +201,13 @@ int i915_gem_init_stolen(struct drm_devi struct drm_i915_private *dev_priv = dev->dev_private; int bios_reserved = 0; +#ifdef CONFIG_INTEL_IOMMU + if (intel_iommu_gfx_mapped) { + DRM_INFO("DMAR active, disabling use of stolen memory\n"); + return 0; + } +#endif + if (dev_priv->gtt.stolen_size == 0) return 0;